This invention relates to inductive charging and communication systems and more specifically to inductive charging and communication systems within a vehicle.
People may carry a variety of personal portable electronic equipment such as PDAs (Personal Data Assistants), portable entertainment devices, such as portable music players or portable DVD players, laptop computers, and cellular telephones. The portable electronic devices provide various functionality such as communication, information storage and retrieval, and entertainment. Since the devices are portable, they are often carried and used in vehicles. The devices are usually battery powered and thus tend to run out of power at inconvenient times.
Power adapters for use in a vehicle are available for such devices. However, each device often has a unique power adapter and chord, requiring that a power adapter for each device either be carried. The power adapter and the attendant chords for attachment to the portable devices are unsightly and clutter the vehicle. Since the power adapter is commonly plugged into the 12 volt DC (direct current) power by way of a cigarette lighter, it also difficult to charge more than one device at a time. Chords and adapters are thereby impractical when several portable devices are used within the vehicle.
Recently, there have been proposals to interface the portable devices to the data network within the vehicle. The SAE (Society of Automotive Engineers) has generally recognized the need for such an interface with an ITS (Intelligent Transportation System) standard. Further, Texas Instruments has proposed an ADB-1394 telematics standard based on the 1394 “firewire” communication standard which would allow portable devices to interface with the electrical systems within the vehicle.
There are problems, however. First, due to the numerous types of portable devices, there are many different types of data interfaces required for each portable device. For example, some devices may have a 1394 interface while others have a USB (Universal Serial Bus) interface. Thus, for a vehicle to interface with a plethora of devices, it may be required to supply a plug for each possible device. Second, due to the number of devices, the number of plugs for each device could be prohibitive as well as the volume of cables required to attach each portable device to the vehicle.
The SAE ITS group has suggested that a wireless network such as the IEEE (Institute of Electrical and Electronic Engineers) 802.11b be provided for each vehicle. The problem with such a wireless network is that the power consumed by the wireless portable device would increase, thereby further increasing the likelihood that the battery powering the portable device would be discharged.
Thus, a system which would provide a data interface for the portable device as well as providing power to the devices is highly desirable.